ok guys heres the problem i have a 86 trans am with a rochester 4 barrel on a 305, It was running way to rich for a few weeks a while back until it just wouldnt run anymore so i had the carb rebuilt and that solved the running rich part but when i start the car no matter how long i let it run it idles in park and neutral at 2000 rpm and even when its in drive. when i shut it off it diesles for a while sometimes 40 seconds long. Ive changed the plugs since its not running rich at all anymore and when i accelerate i hear a pinging noise, but i dont hear anything when i rev it in neutral or park. When i checked my timming my veci label didnt say anything about a est connector it said dissconect a 4 wire conecter at the distributor the only one i could find went to the back so i disconected that and checked my timming i cant read the tab but the tech article says the peak to the left of the big v is 4* advanced and thats right where mine is. also when i disconect that 4 wire connecter it idles fine at 700 rpm. oh yeh one more thing since i put the carb back on the car wont shift into second till about 2500 rpms but i think that might just be that my t.v. cable might need a little adjusment not sure if it had anything to do with me problem tho. what do you thinks wrong with my car?

Thanks, joe

 

Check the thermostat for the high RPMs, if its stuck open, then your engine will always run cool, i guess I should ask if your engine runs cool?

 

it comes up to temp just fine, no problems at all with the coolent system, that i know of at least

 

When you reinstalled the carb, did you check to make sure the PCV was connected? I overlooked this once after changing the valve cover on the drivers side and had the same problems. Now that I've switched carbs, I tried it with and without the valve connected and sure enough it was the problem curing the high idle.

 

Probably a large vacuum leak somewhere that is providing air under the throttle blades. If the carb is dripping any gas after key off, that combined with the vac leak is sometimes enough to make it deisel, and the vacuum leak will definately raise the idle.

 

Had the same problem!!!!!!!


It's the electromic choke, your running with the choke on full time.
find the choke lead on the carb and reaverse it so that it's the other way around, about a 180 degree turn.

 

You do realize that a single symptom could have dozens, if not hundreds of causes, right? Just because this is what was causing it on your car does not mean that it is the only thing that can cause it on all cars...

 

ok heres some more info; I forgot to mention that my emmisions system is not all there, theres hoses goin nowhere and the pump doesnt have anything runnin to it not even a belt, previous owner apperently didnt like the emission control system but not enough to finish the job, could that have anything to do with it? the pcv is conected to the valve cover and carb, also when i disconect the 4 wire harness at the dist it idles awsome at 900 rpms. I really dont want to take the car to the shop cause im affraid of what they would charge me and i leave for bootcamp in a month and a half so i just want to enjoy the nice weather with the t-tops off before i go

Thanks joe

 

it sounds like your electronic advance dizzy may be bad. or something in that area. diesling and popping (known as detonation) occur when the timing is too far advanced. make sure your timing marker is actually accurate, they get bent, mangled, sometimes removed with aftermarket parts. make sure the mark on your harmonic balancer is right. but it really sounds like there is a problem inside of the dizzy. look there before you start blaming the carb. it seems like most carb problems are actually ignition problems.

 

I was assuming by deiseling, he meant "run-on" after the car was shut off. I could be wrong though

 

yes, and if you go out and crank your dizzy to far advance, it will try to run on.